package cn.runagain.demo.wechatminiappdemo.aes;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;

/**
 * created by
 *
 * @author tuxianchao
 * @date 2018/6/14 上午12:17
 */
public class AesDemo {
    /**
     *
     */
    private static final String DEFAULT_CHARSET = "UTF-8";
    /**
     *
     */
    private static final String KEY_AES = "AES";
    /**
     *
     */
    private static final String KEY = "0bc406a1-92b3-4db4-9a05-034adede912b";

    /**
     * 二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String byte2HexStr(byte[] buf) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public static byte[] hexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length() / 2];
        int num2 = 2;
        for (int i = 0; i < hexStr.length() / num2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

    /**
     * 加密
     *
     * @param data 待加密的内容
     * @param key  加密秘钥
     * @return
     */
    public static String encrypt(String data, String key) {
        return aes(data, key, Cipher.ENCRYPT_MODE);
    }

    /**
     * 解密
     *
     * @param data 待解密内容
     * @param key  解密密钥
     * @return
     */
    public static String decrypt(String data, String key) {
        return aes(data, key, Cipher.DECRYPT_MODE);
    }

    private static String aes(String data, String key, int mode) {
        try {
//            if (StringUtils.isBlank(data) || StringUtils.isBlank(key)) {
//                return null;
//            }
            if ("".equals(data) || "".equals(key)) {
                return null;
            }
            //加密模式or解密模式
            boolean encrypt = (mode == Cipher.ENCRYPT_MODE);
            byte[] content;
            //true-加密,false-解密内容
            if (encrypt) {
                content = data.getBytes(DEFAULT_CHARSET);
            } else {
                content = hexStr2Byte(data);
            }
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(key.getBytes());

            //1.构造密钥生成器，指定为AES算法,不区分大小写
            KeyGenerator kgen = KeyGenerator.getInstance(KEY_AES);
            //2.根据ecnodeRules规则初始化密钥生成器.生成一个128位的随机源,根据传入的字节数组
//            kgen.init(128, new SecureRandom(key.getBytes()));
            kgen.init(128, random);
            //3.产生原始对称密钥
            SecretKey secretKey = kgen.generateKey();
            //4.获得原始对称密钥的字节数组
            byte[] enCodeFormat = secretKey.getEncoded();
            //5.根据字节数组生成AES密钥
            SecretKeySpec keySpec = new SecretKeySpec(enCodeFormat, KEY_AES);
            //6.根据指定算法AES自成密码器,// 创建密码器
            Cipher cipher = Cipher.getInstance(KEY_AES);
            //7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作，第二个参数为使用的KEY,// 初始化
            cipher.init(mode, keySpec);
            byte[] result = cipher.doFinal(content);
            if (encrypt) {
                //将二进制转换成16进制
                return byte2HexStr(result);
            } else {
                return new String(result, DEFAULT_CHARSET);
            }
        } catch (Exception e) {
            System.out.println(("AES 密文处理异常" + e));
        }
        return null;
    }

    public static void main(String[] args) {
//        String content = "{'repairPhone':'18547854787','customPhone':'12365478965','captchav':'58m7'}";
//        Long content = 100000000001L;
//        String content = "站在云端，敲下键盘，望着通往世界另一头的那扇窗，只为做那读懂0和1的人。。";
        String content = "hweiofuhwoiyhiqwjoyqowy";
        System.out.println("加密前:" + content);
        System.out.println("加密密钥和解密密钥:" + KEY);

        String encrypt = encrypt(content + "", KEY);
        System.out.println("加密后:" + encrypt);


        String decrypt = decrypt(encrypt, KEY);
        System.out.println("解密后:" + decrypt);
    }
}
